feat: adding config for stubbing (#360)

* fix: only stub `process.env` if not targeting node

* fix: use better replacement

* only dont stub on main thread electron

* add tests that use the compiler

* start converting old tests

* move more tests

* replace old tests

* fix errors

* fix race condition

* handle no dir error

* remove behavior changes

* drop node 8

* undo more fixes

* fix stubbing replacement, only stub on targets where we should

* remove deprecated code

* drop support for webpack <4

* merge stubIgnore PR

* update readme

* fix logic

* Update README.md

* skip stubbing on webpack 4, do not stub if target includes `node`

* handle target array

* move version check

* fix logic

* replace usage of `rmdirSync(..., { recursive: true })`

BREAKING CHANGE: dropping support for Node v8

BREAKING CHANGE: dropping support for webpack < 4

BREAKING CHANGE: automatically stubbing during compilation

.github/workflows/main.yml

@@ -48,7 +48,7 @@ jobs:
     runs-on: ubuntu-18.04
     strategy:
       matrix:
-        node: [ '8', '10', '12', '14' ]
+        node: [ '10', '12', '14' ]
     steps:
       - name: 🛑 Cancel Previous Runs
         uses: styfle/cancel-workflow-action@0.6.0

.gitignore

@@ -1,3 +1,6 @@
+# Tests
+test/output
+
 # Logs
 logs
 *.log

README.md

@@ -95,6 +95,14 @@ Add `.env` to your `.gitignore` file
 
 Due to the fact that we use `webpack.DefinePlugin` under the hood, we cannot support destructing as that breaks how this plugin is meant to be used. Because of this, please reference your variables without destructing. For more information about this, please review the issue [here](https://github.com/mrsteele/dotenv-webpack/issues/70).
 
+## `process.env` stubbing / replacing
+
+`process.env` is not polyfilled in Webpack 5+, leading to errors in environments where `process` is `null` (browsers).
+
+We automatically replace any remaining `process.env`s in these environments with `"MISSING_ENV_VAR"` to avoid these errors.
+
+If you are running into issues where you or another package you use interfaces with `process.env`, it might be best to set `ignoreStubs: true` and make sure you always reference variables that exist within your code (See [this issue](https://github.com/mrsteele/dotenv-webpack/issues/271) for more information).
+
 ## Properties
 
 Use the following properties to configure your instance.
@@ -106,6 +114,7 @@ Use the following properties to configure your instance.
 * **silent** (`false`) - If true, all warnings will be suppressed.
 * **expand** (`false`) - Allows your variables to be "expanded" for reusability within your `.env` file.
 * **defaults** (`false`) - Adds support for `dotenv-defaults`. If set to `true`, uses `./.env.defaults`. If a string, uses that location for a defaults file. Read more at [npm](https://www.npmjs.com/package/dotenv-defaults).
+* **ignoreStub** (`false`) - Override the automatic check whether to stub `process.env`. [Read more here](#user-content-processenv-stubbing--replacing).
 
 The following example shows how to set any/all arguments.
 

package.json

@@ -21,7 +21,10 @@
   },
   "jest": {
     "coverageDirectory": "./coverage/",
-    "collectCoverage": true
+    "collectCoverage": true,
+    "watchPathIgnorePatterns": [
+      "output/.*?"
+    ]
   },
   "keywords": [
     "dotenv",
@@ -41,8 +44,11 @@
     "url": "https://github.com/mrsteele/dotenv-webpack/issues"
   },
   "homepage": "https://github.com/mrsteele/dotenv-webpack#readme",
+  "engines": {
+    "node": ">=10"
+  },
   "peerDependencies": {
-    "webpack": "^1 || ^2 || ^3 || ^4 || ^5"
+    "webpack": "^4 || ^5"
   },
   "dependencies": {
     "dotenv-defaults": "^2.0.1"
@@ -52,6 +58,7 @@
     "@babel/core": "^7.13.8",
     "@babel/preset-env": "^7.13.9",
     "@babel/register": "^7.13.8",
+    "fs-extra": "^9.1.0",
     "husky": "^5.1.3",
     "jest": "^25.5.4",
     "jsdoc": "^3.6.6",

src/index.js

@@ -16,6 +16,9 @@ const interpolate = (env, vars) => {
   return env
 }
 
+const isMainThreadElectron = (target) =>
+  target.startsWith('electron') && target.endsWith('main')
+
 class Dotenv {
   /**
    * The dotenv-webpack plugin.
@@ -30,21 +33,19 @@ class Dotenv {
     this.config = Object.assign({}, {
       path: './.env'
     }, config)
-
-    this.checkDeprecation()
-
-    return new DefinePlugin(this.formatData(this.gatherVariables()))
   }
 
-  checkDeprecation () {
-    const { sample, safe, silent } = this.config
-    // Catch older packages, but hold their hand (just for a bit)
-    if (sample) {
-      if (safe) {
-        this.config.safe = sample
-      }
-      this.warn('dotenv-webpack: "options.sample" is a deprecated property. Please update your configuration to use "options.safe" instead.', silent)
-    }
+  apply (compiler) {
+    const variables = this.gatherVariables()
+    const target = compiler.options.target ?? 'web'
+    const version = compiler.webpack.version
+    const data = this.formatData({
+      variables,
+      target,
+      version
+    })
+
+    new DefinePlugin(data).apply(compiler)
   }
 
   gatherVariables () {
@@ -121,10 +122,10 @@ class Dotenv {
     return ''
   }
 
-  formatData (vars = {}) {
+  formatData ({ variables = {}, target, version }) {
     const { expand } = this.config
-    const formatted = Object.keys(vars).reduce((obj, key) => {
-      const v = vars[key]
+    const formatted = Object.keys(variables).reduce((obj, key) => {
+      const v = variables[key]
       const vKey = `process.env.${key}`
       let vValue
       if (expand) {
@@ -133,7 +134,7 @@ class Dotenv {
         } else if (v.indexOf('\\$') > 0) {
           vValue = v.replace(/\\\$/g, '$')
         } else {
-          vValue = interpolate(v, vars)
+          vValue = interpolate(v, variables)
         }
       } else {
         vValue = v
@@ -144,12 +145,39 @@ class Dotenv {
       return obj
     }, {})
 
-    // fix in case of missing
-    formatted['process.env'] = '{}'
+    // We have to stub any remaining `process.env`s due to Webpack 5 not polyfilling it anymore
+    // https://github.com/mrsteele/dotenv-webpack/issues/240#issuecomment-710231534
+    // However, if someone targets Node or Electron `process.env` still exists, and should therefore be kept
+    // https://webpack.js.org/configuration/target
+    if (this.shouldStub({ target, version })) {
+      // Results in `"MISSING_ENV_VAR".NAME` which is valid JS
+      formatted['process.env'] = '"MISSING_ENV_VAR"'
+    }
 
     return formatted
   }
 
+  shouldStub ({ target: targetInput, version }) {
+    if (!version.startsWith('5')) {
+      return false
+    }
+
+    const targets = Array.isArray(targetInput) ? targetInput : [targetInput]
+
+    return targets.every(
+      target =>
+        // If we're not configured to never stub
+        this.config.ignoreStub !== true &&
+        // And
+        (
+          // We are configured to always stub
+          this.config.ignoreStub === false ||
+          // Or if we should according to the target
+          (!target.includes('node') && !isMainThreadElectron(target))
+        )
+    )
+  }
+
   /**
    * Load a file.
    * @param {String} config.file - The file to load.

test/fixtures/index.js

@@ -0,0 +1,28 @@
+/* eslint-disable no-unused-vars */
+
+// Basic
+const TEST = process.env.TEST
+const TEST2 = process.env.TEST2
+
+// System
+const PATH = process.env.PATH
+
+// Expanded
+const NODE_ENV = process.env.NODE_ENV
+const BASIC = process.env.BASIC
+const BASIC_EXPAND = process.env.BASIC_EXPAND
+const MACHINE = process.env.MACHINE
+const MACHINE_EXPAND = process.env.MACHINE_EXPAND
+const UNDEFINED_EXPAND = process.env.UNDEFINED_EXPAND
+const ESCAPED_EXPAND = process.env.ESCAPED_EXPAND
+const MONGOLAB_DATABASE = process.env.MONGOLAB_DATABASE
+const MONGOLAB_USER = process.env.MONGOLAB_USER
+const MONGOLAB_PASSWORD = process.env.MONGOLAB_PASSWORD
+const MONGOLAB_DOMAIN = process.env.MONGOLAB_DOMAIN
+const MONGOLAB_PORT = process.env.MONGOLAB_PORT
+const MONGOLAB_URI = process.env.MONGOLAB_URI
+const MONGOLAB_USER_RECURSIVELY = process.env.MONGOLAB_USER_RECURSIVELY
+const MONGOLAB_URI_RECURSIVELY = process.env.MONGOLAB_URI_RECURSIVELY
+const WITHOUT_CURLY_BRACES_URI = process.env.WITHOUT_CURLY_BRACES_URI
+const WITHOUT_CURLY_BRACES_USER_RECURSIVELY = process.env.WITHOUT_CURLY_BRACES_USER_RECURSIVELY
+const WITHOUT_CURLY_BRACES_URI_RECURSIVELY = process.env.WITHOUT_CURLY_BRACES_URI_RECURSIVELY